async_tx: expand async raid6 test to cover ioatdma corner case

Add explicit 11 and 12 disks cases to exercise the 0 < src_cnt % 8 < 3
corner case in the ioatdma driver.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/crypto/async_tx/raid6test.c b/crypto/async_tx/raid6test.c
index 3ec27c7..f84f6b4 100644
--- a/crypto/async_tx/raid6test.c
+++ b/crypto/async_tx/raid6test.c
@@ -214,6 +214,13 @@
 		err += test(4, &tests);
 	if (NDISKS > 5)
 		err += test(5, &tests);
+	/* the 11 and 12 disk cases are special for ioatdma (p-disabled
+	 * q-continuation without extended descriptor)
+	 */
+	if (NDISKS > 12) {
+		err += test(11, &tests);
+		err += test(12, &tests);
+	}
 	err += test(NDISKS, &tests);
 
 	pr("\n");